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CHAPTER 5 The Hemoflagellates
Posterior end
Nucleus
Anterior end
Parabasal body
Kinetoplast
Blepharoplast
Undulating membrane
Flagellum
Size range: 9-15 m long
FIGURE 5-4 Epimastigote.
Posterior end
Nucleus
Undulating membrane
Anterior end
Axoneme
Blepharoplast
Parabasal body
Kinetoplast
Size range: 12-35 m by 2-4 m
FIGURE 5-5 Trypomastigote.
Flagellum
TABLE 5-3
Parameter
Size
Appearance
Nucleus
Other features
Epimastigote: Typical
Characteristics at a Glance
Description
9-15 µm long
Long and slightly wider than
promastigote form
One, located in posterior end
Kinetoplast located anterior to
the nucleus
Undulating membrane, extending
half of body length
Free flagellum, extending from
anterior end
Trypomastigotes. The typical trypomastigote
measures 12 to 35 µm long by 2 to 4 µm wide,
and may often assume the shape of the letters C,
S or U in stained blood films (Figs. 5-5 to 5-7;
Table 5-4). The trypomastigote in Figure 5-5 is
represented in its straight form for comparison
purposes because it clearly denotes the individual
structures. The long slender organism is characterized
by a posteriorly located kinetoplast from
which emerges a full body length undulating
membrane. The single large nucleus is located
anterior to the kinetoplast. An anterior free flagellum
may or may not be present.
that of the promastigote. The large single nucleus
is located in the posterior end of the organism.
The kinetoplast is located anterior to the nucleus.
An undulating membrane, measuring half the
body length, forms into a free flagellum at the
anterior end of the epimastigote.
General Morphology and Life
Cycle Notes
The amastigote and trypomastigote are the two
forms routinely found in human specimens.
Amastigotes are found primarily in tissue and